This invention relates to dynamoelectric machines and more particularly, to a leadless electric motor. While the invention is described with a particular reference to a unit bearing, shaded pole ac induction motor, those skilled in the art will recognize the wider applicability of the inventive principles disclosed hereinafter.
Dynamoelectric machines, particularly, both ac and dc motors, commonly include a core formed from a plurality of individual laminations. The core has winding receiving slots formed in it, and a winding is positioned on the core along the slots. The physical ends of the windings commonly are connected to internal electrical leads, which in the past have been brought externally of the motor. The leads are used to connect the motor to a source of external electrical energy. More recently, motor manufacturing efforts have been directed toward developing leadless motors. An example of such construction is shown in U.S. Pat. No. 5,015,894, issued May 14, 1991, and assigned to the assignee of the present invention. The disclosure of the 5,015,894 patent is intended to be incorporated herein by reference. As pointed out in that patent, electrical leads and their interconnection add cost to the motor. Among other reasons for such added cost is the fact that leads inhibit automation of the motor manufacturing process. Elimination of leads would facilitate automation and reduce manufacturing costs. Leadless motors also are more easily shipped, and the ability to simplify the shipping process also leads to reduced costs.
Unit bearing motors also are well known in the art. Specific reference to their construction may be found, for example, in U.S. Pat. Nos. 4,209,722 and 4,499,661, the disclosures of which are intended to be incorporated herein by reference. Both patents are assigned to the assignee of the present invention. Unit bearing motors are widely used in a number of condenser fan applications, having become ubiquitous in such applications as refrigerators and small room air conditioners.
Because of their wide acceptance in commercial products, certain safety features are required in the motor design. These features include, for example, a ground connection for the motor. Incorporating a ground connection easily in the receptacle design so as to permit automation of the motor manufacturing process is a continuing problem for motor manufacturers.
In addition, because the motor is leadless, and intended for application by original equipment manufacturers' personnel, the receptacle must be designed for foolproof installation of the power leads for the motor. Another problem facing motor manufacturers is the ability easily to color code the motor so that various ratings or motor types may be visually apparent to an OEM. Our invention overcomes these leadless prior art difficulties with a simply constructed, easily automated motor construction.